The Series 100 and 150 continuous winders manufactured by Paper Converting Machine Company and as described in U.S. Pat. Nos. 2,769,600--Kwitek et al and 3,179,348--Nystrand et al are representative of the prior art. Those automatic web rewinding machines have a turret mounted for rotation within a frame which is pivotally mounted in the machine. The turret includes six rotatable mandrel assemblies. The web being rewound from a parent roll passes over a bedroll of the machine and is wound about a core placed on a mandrel assembly located at a winding station adjacent to the bedroll. A fresh core, with glue applied to the core, is mounted on the mandrel assembly that will next approach the winding station. As the winding of the roll at the winding station nears completion, the turret begins to index, or rotate, and the frame is caused to swing toward the bedroll so that the fresh core is brought into close proximity to the bedroll. The web is then severed and the free end of the web from the parent roll is caused to be transferred to the glue on the fresh core to begin the winding of a roll on the fresh core. Immediately after transfer, the turret swings away from the bedroll so that the roll being wound does not contact the bedroll. Before the turret finishes indexing it is necessary to swing the turret to a dwell position at which the next fresh core which has glue freshly applied to it; will not prematurely contact the web during the winding process. After the turret has completed indexing, or rotating 60 degrees, it dwells in that position for a considerable period of time during which a completely wound roll can be stripped from a mandrel assembly located adjacent to a stripping station and a fresh core can be placed onto a mandrel assembly that is located adjacent to a supply of cores.
In the prior art machines, the swing of the frame and turret assembly is controlled by a cam mounted for rotation on the frame which cooperates with a roller assembly mounted in the machine. As the cam rotates, the periphery of the cam controls the angle of rotation of the frame and, therefore, the location of the freshly glued core with respect to the web being wound and the bedroll. In the prior art machines, an internal Geneva mechanism is used to control the indexing of the turret. The internal Geneva mechanism has an input shaft and an output shaft, and for one continuous revolution of the input shaft, the output shaft dwells 33 percent of the time and causes the turret to rotate through 1.05 radians during the remainder of the time. In the prior art machines, the cam is geared to the input shaft to the internal Geneva mechanism so that it makes one continuous revolution for each indexing cycle of the turret. Since it is only desired to swing the turret while it is indexing, 33 percent of the cam surface is not available to control the swinging of the turret.
Attempts have been made to increase the productivity of the prior art automatic web rewinding machines by running them at a higher cycle rate. When operated at these higher cycle rates, it has been found that the reduced dwell time of the turret is insufficient to reliably strip a completely wound core from the mandrel assembly, or to place a fresh core onto a mandrel assembly. Another problem that is encountered at the higher cycle rate is increased vibration and backlash of the turret which sometimes causes poor transfers of the web to the fresh core or tearing of the web during the winding of the roll. This increased vibration and backlash is caused by high pressure angles at the point of contact of the cam periphery and the roller. It was believed that a more effective transfer of the web to the fresh core would take place if the transfer occurred "higher up on the bedroll", which occurs by swinging the turret further toward the bedroll at transfer so that the vertical distance between the axis of the mandrel that is approaching the winding station and the axis of the bedroll is increased over that of the prior art machines. Normally this would be accomplished by shaping the cam so that the frame and turret assembly undergo the desired additional motion toward the bedroll. However, when it was attempted to design a cam to provide this additional rotation of the frame and turret assembly, it was found that the cam could not be physically realized because such a cam would be "under cut".
Another prior art automatic web rewinding machine is the series 200 continuous winder manufactured by Paper Converting Machine Company. In this machine, the intermittently rotating turret is mounted in a stationary frame. As in the case of the series 100 and 150 rewinding machines, during the indexing of the turret, it is necessary to prevent the fresh core with the glue applied thereto from coming in contact with the web that is being wound. This is accomplished by means of a moving deflector bar, driven in synchronism with the turret, which causes the web to be deflected toward and in close proximity to the bedroll which keeps the web out of the path of the freshly glued core. Although the series 200 automatic web rewinding machine, which operates at a higher cycle rate than the series 100 and 150 machines is commercially available, the increase in productivity does not justify the purchase of a new machine to replace the swinging turret model. It is also not economically feasible to modify the swinging turret machines to have a fixed turret frame and to incorporate a web deflector bar.